1. Field of the Invention
The present invention pertains to harvesting machinery particularly to toppers for use on harvesting machines, and especially for machines for harvesting crops such as sugar cane. Sugar cane grows in the form of tall stalks with long ribbon-like leaves. A concentration of the leaves is located on the upper parts of these stalks, known as the tops. The tops are not used in production of sugar cane juice and its products and must be removed before the remainders of the stalks are gathered for processing.
The machines used for harvesting sugar cane are usually vehicles which can move through the cane field cutting the cane as they go. They include means for drawing the stalks into a narrow portion of the machine where they are cut. A lower knife cuts the entire cane stalk off near the ground, and a topper cuts off the top. The topper includes some type of deflecting structure for flipping the cut tops to one side of the machine or the other. It is most desirable to have a deflecting structure which is reversible so that the cane tops can be deflected to either side desired.
2. Description of the Prior Art
One type of deflector used in prior art toppers was in the form of a paddle rotatably mounted above the knife of the topper. The paddle was disposed at an angle to a true radius of its axis so as to better project the cane to the desired side of the machine without catching the leaves. To reverse the direction of deflection, it was necessary to remove the paddle from the machine and turn it over so as to reverse the angle. This arrangement was inconvenient and time consuming.
Another type of topper employed a deflecting structure in the form of a regular polygonal box which could be rotated in either direction by reversible drive means. The flat walls of the box formed deflecting surfaces which would deflect the cane in the direction of rotation. Although easier to reverse than the other type of deflector, the box was difficult and indeed impossible to fabricate perfectly symmetrically. Even when constructed as symmetrically as possible, it often caused vibration problems as it was rotated about its axis.
Another known type of topper included a cylindrical core having a plurality of radially extending blades. This type as the disadvantage that the ribbon-like leaves of the cane tend to become caught on the blades and carried around and into the machinery, a phenomenon known as "backfeeding". This type of topper as well as the box type described above are disclosed in prior U.S. Pat. No. 3,772,864.